Review
Physics, Multidisciplinary
Viktor Holubec, Artem Ryabov
Summary: The study of fluctuations in the performance of small heat engines has gained attention due to the development of microscopic machines. Understanding these fluctuations may lead to a revolution similar to the discovery of the second law of thermodynamics.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2022)
Article
Physics, Multidisciplinary
Yuto Ashida, Takahiro Sagawa
Summary: Researchers have developed a reinforcement learning framework to optimize power and efficiency in nanoscale engines with significant two-body interactions. They found that electron-electron interactions can significantly enhance thermal performance, providing an alternative strategy for designing the best heat engines with multiple objectives.
COMMUNICATIONS PHYSICS
(2021)
Article
Physics, Fluids & Plasmas
Gonzalo Manzano, Edgar Roldan
Summary: This study derives universal bounds for the finite-time survival probability of stochastic work extracted and stochastic heat dissipated in steady-state heat engines. It also provides estimates for the time-dependent thresholds that these quantities do not surpass with a given probability. The tightest thresholds at long times are found to be proportional to the large deviation functions of stochastic entropy production. Moreover, this research extends martingale theory for entropy production, deriving universal inequalities involving maximum and minimum statistics that are valid for generic Markovian dynamics in nonequilibrium stationary states.
Article
Physics, Multidisciplinary
Lingen Chen, Giulio Lorenzini
Summary: Cycle model extension and universalization is a significant topic in finite time thermodynamics (FTT) studies. This paper establishes a universal generalized irreversible steady flow refrigeration cycle model with various irreversible processes and loss items using FTT. It derives expressions for five performance indicators and analyzes the effects of cycle processes and loss items on these indicators using numerical examples.
EUROPEAN PHYSICAL JOURNAL PLUS
(2022)
Article
Quantum Science & Technology
Mohit Lal Bera, Maciej Lewenstein, Manabendra Nath Bera
Summary: Researchers have achieved a breakthrough in heat engines operating in the one-shot finite-size regime, where engines allow working systems to interact with two baths simultaneously and operate reversibly in a one-step cycle, thus achieving Carnot efficiency.
NPJ QUANTUM INFORMATION
(2021)
Article
Physics, Multidisciplinary
Julio J. Fernandez
Summary: We study the similarities and differences between one-qubit Novikov quantum heat engines and classic Novikov heat engines. We find that they have similar power-efficiency curves but very different ecological function-efficiency curves. Our analysis shows that in quantum engines, the maximum values of power and ecological function, as well as the efficiencies at which they are produced, depend on thermal couplings and the energy of the qubit inducing the heat flux that makes the engine work.
EUROPEAN PHYSICAL JOURNAL PLUS
(2023)
Article
Environmental Sciences
Deniz Berfin Karakoc, Megan Konar
Summary: Global food trade plays a crucial role in food security and availability. Research shows that there is a competitive relationship between efficiency and resilience in food trade networks when only network topology is considered, but a cooperative relationship exists when trade connection intensity is taken into account. This complex network framework can assist policymakers in evaluating the relationship between efficiency and resilience in critical supply chains.
ENVIRONMENTAL RESEARCH LETTERS
(2021)
Review
Engineering, Chemical
Yanan Zhao, Mingliang Li, Rui Long, Zhichun Liu, Wei Liu
Summary: This study presents a comprehensive review of osmotic heat engines (OHEs), discussing their types, characteristics, and related heat-to-work thermodynamic systems. The potential applications and critical assessment of OHEs are also discussed, along with the technological challenges and research perspectives.
Article
Computer Science, Information Systems
Ivan Popovic, Strahinja Jankovic
Summary: The methodology proposed introduces metrics for modeling application performance and techniques for its control, enabling more efficient power-performance trade-off management. It allows for selective system performance degradation and fine-grained control of system behavior in the power-performance domain by extending the set of controllable operating point parameters through real-time applications. The methodology's utilization and effectiveness are evaluated in a simulated environment for various application execution scenarios, including system operation beyond utilization bounds.
Article
Thermodynamics
Julian D. Osorio, Alejandro Rivera-Alvarez, Obie Abakporo, Juan C. Ordonez, Rob Hovsapian
Summary: In this paper, a thermodynamic model based on the endoreversible engine approach is developed to analyze the performance of heat engines under different thermodynamic cycles. The model considers finite heat transfer rate, variable heat source and sink temperatures, and irreversibilities associated with expansion and compression. Expressions for the maximum power and efficiency at maximum power output are obtained, taking into account the hot and cold reservoir temperatures, the equivalent isentropic efficiency, and the effective conductance ratio between heat exchangers. The proposed model allows for assessing the impact of isentropic efficiencies and heat exchanger design and operation characteristics on various thermodynamic cycles.
JOURNAL OF THERMAL SCIENCE AND ENGINEERING APPLICATIONS
(2022)
Article
Thermodynamics
S. M. Hosseinimaab, A. M. Tousi
Summary: This study presents a new method for analyzing the simulation and off-design performance of gas turbine engines, successfully applied to the performance testing of the Olympus-HP micro turbojet engine. The research also explores the off-design performance of a double-shaft gas turbine, providing important insights for evaluating the impact of environmental changes on engine performance.
ENERGY CONVERSION AND MANAGEMENT
(2021)
Article
Physics, Fluids & Plasmas
Varinder Singh, Satnam Singh, Obinna Abah, Ozgur E. Mustecaplioglu
Summary: We investigate the quantum Otto engine and refrigeration cycles of a time-dependent harmonic oscillator, exploring the conditions of maximum Q function. We derive analytical expressions for the efficiency and coefficient of performance of the Otto cycle, and observe interesting behaviors including the mapping of the harmonic Otto engine to Feynman's ratchet and pawl model and loop-like behavior of the efficiency-work curve for sudden frequency switches. Furthermore, we discuss the behavior of cooling power at maximum Q function.
Article
Physics, Multidisciplinary
Tobias Denzler, Eric Lutz
Summary: The efficiency of small thermal machines is typically a fluctuating quantity. We analytically computed the joint characteristic functions for heat and work of two exemplary quantum heat engines, and found that work and heat are perfectly anticorrelated for generic scale-invariant quantum heat engines under adiabatic driving.
NEW JOURNAL OF PHYSICS
(2021)
Article
Nanoscience & Nanotechnology
Xiaoguang Luo, Hexin Zhang, Dan Liu, Nannan Han, Dong Mei, Jinpeng Xu, Yingchun Cheng, Wei Huang
Summary: The study demonstrates that the limit efficiency at maximum power (EMP) of a thermoelectric heat engine can be achieved by resonant tunneling in the InP/InSe superlattice, where a strong coupling between symmetric mode and Fabry-Pe?rot modes is realized. Optimizing the bias voltage and the thicknesses of barrier and well can extract more than 95% of the theoretical limits of maximum power and EMP.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2021)
Article
Thermodynamics
Rui Long, Yanan Zhao, Mingliang Li, Yao Pan, Zhichun Liu, Wei Liu
Summary: This study investigates a methanol-based adsorption-driven osmotic heat engine for recovering low temperature waste heat, providing criteria for selecting appropriate adsorbents and achieving a maximum energy efficiency through numerical analysis and experimentation.
Article
Physics, Mathematical
Oliver Niggemann, Udo Seifert
Summary: This study tests a general framework for the field-theoretic thermodynamic uncertainty relation by directly simulating the KPZ equation, and finds good agreement with analytical predictions under the weak coupling limit. However, the accuracy of numerical results varies with the choice of discretization of the KPZ non-linearity, and an inherent limitation to the accuracy of the total entropy production approximation is discovered, which is explained to be an intrinsic property of the discretization scheme used.
JOURNAL OF STATISTICAL PHYSICS
(2021)
Article
Physics, Multidisciplinary
Lukas Oberreiter, Udo Seifert, Andre C. Barato
Summary: A thermodynamically consistent model for discrete time crystals is introduced and analyzed using stochastic thermodynamics. The study reveals that coherent oscillations can emerge even in the absence of synchronization. The mean-field model displays subharmonic synchronization while the 2D model shows a time-crystalline phase.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Timur Koyuk, Udo Seifert
Summary: The thermodynamic uncertainty relation allows inferring total entropy production rate by observing current or state variables. Suitable observables can be found for estimating total entropy production in both fast and slow driving cases. The uncertainty relation can even be saturated in the limit of fast driving.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2021)
Article
Physics, Mathematical
Oliver Niggemann, Udo Seifert
Summary: Investigation on the thermodynamic uncertainty relation in the (1 + 1) dimensional KPZ equation with finite spatial interval reveals two distinct regimes of the relation separated by a critical coupling parameter. Analytical exploration of the asymptotic behavior below and above the critical threshold is presented, along with comparison to numerical simulations.
JOURNAL OF STATISTICAL PHYSICS
(2022)
Article
Physics, Multidisciplinary
Patrick Pietzonka
Summary: The thermodynamic uncertainty relation is a universal trade-off between driving an autonomous system and the precision of output observable. It has been proven for discrete systems and overdamped Brownian motion, but the validity for underdamped Brownian motion remains uncertain. Through constructing a counterexample inspired by a pendulum clock, we disprove the conjecture and show that the uncertainty relation is broken by underdamped harmonic oscillators in thermal equilibrium.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Jann van der Meer, Benjamin Ertel, Udo Seifert
Summary: This work investigates the waiting time distributions between consecutive transitions in a partially observable Markov network. An entropy estimator is formulated using the ratios of waiting time distributions to quantify irreversibility. Depending on the complexity of the underlying network, criteria are formulated to infer whether the entropy estimator recovers the full physical entropy production or provides a lower bound. Additionally, estimators for the network topology are derived using an equivalent semi-Markov description. The study provides a unifying mathematical framework for entropy estimators and clarifies the meaning of formal versus physical irreversibility.
Article
Physics, Multidisciplinary
Arya Datta, Patrick Pietzonka, Andre C. Barato
Summary: Macroscopic cyclic heat engines have been a major motivation for the emergence of thermodynamics. In recent years, cyclic heat engines that have large fluctuations and operate at finite time have been studied within the framework of stochastic thermodynamics. This study examines the concept of cyclic active heat engines for systems with hidden dissipative degrees of freedom and introduces a general second law for active heat engines using a known inequality in stochastic thermodynamics.
Article
Physics, Multidisciplinary
Josip Augustin Janes, Cornelia Monzel, Daniel Schmidt, Rudolf Merkel, Udo Seifert, Kheya Sengupta, Ana-Suncana Smith
Summary: This article investigates the influence of active fluctuations on reaction kinetics in a medium, using the cell membrane as a paradigmatic example. By deriving binding and unbinding rates from first principles and establishing a model that incorporates both thermal fluctuations and active fluctuations, the authors show that these fluctuations directly impact protein association and dissociation rates.
Article
Physics, Multidisciplinary
Timur Koyuk, Udo Seifert
Summary: This paper investigates the properties of the thermodynamic uncertainty relation (TUR) in complex systems with many degrees of freedom. By analyzing the entropy production of mixtures of driven particles, an explicit expression for the optimal estimate of total entropy production is derived and applied to driven lattice gases.
PHYSICAL REVIEW LETTERS
(2022)
Article
Biochemistry & Molecular Biology
Benjamin Ertel, Jann van der Meer, Udo Seifert
Summary: In this study, we propose a method to extract the step size and stalling force of a molecular motor without relying on external control parameters. The method is non-invasive, operationally accessible in experiments, and can potentially be applied to any model describing the dynamics of molecular motors. Our results are confirmed by extensive numerical simulations.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Physics, Multidisciplinary
Jann van der Meer, Julius Deguenther, Udo Seifert
Summary: Irreversibility is quantified by entropy production, which can be estimated through measuring antisymmetric observables like current. A general framework is introduced to infer a lower bound on entropy production by measuring time-resolved statistics of events with any symmetry under time reversal, including time-symmetric instantaneous events. Markovianity is emphasized as a property of certain events rather than the full system, and an operationally accessible criterion for this weakened Markov property is introduced. The approach is based on snippets, which are particular sections of trajectories between two Markovian events, and a generalized detailed balance relation is discussed.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Fluids & Plasmas
Lukas Oberreiter, Udo Seifert, Andre C. Barato
Summary: Biochemical clocks are crucial for all living systems and can only oscillate coherently for a limited number of times when isolated from external signals and subject to fluctuations. Moreover, these clocks can only oscillate if they consume free energy. We propose a universal bound that determines the minimum amount of free energy required for a certain number of coherent oscillations.
Article
Physics, Fluids & Plasmas
Benjamin Ertel, Jann van der Meer, Udo Seifert
Summary: This article discusses the relationship between entropy production and mean and variance of steady-state currents in semi-Markov processes, as well as the uncertainty relation in coarse-grained Markov processes generated by semi-Markov descriptions. The article introduces a crucial condition in thermodynamic consistency and presents some alternative derivations of results.
Article
Physics, Fluids & Plasmas
Benedikt Remlein, Volker Weissmann, Udo Seifert
Summary: In this study, we analytically determine the quality factor of oscillations induced by driven Fokker-Planck dynamics along a periodic one-dimensional potential in a noisy environment. We extend this approach to investigate motion along a noisy two-dimensional limit cycle and apply it to the Stuart-Landau oscillator and the Brusselator chemical clock model. Our approach complements the existing framework based on Hamilton-Jacobi theory and is compared with numerical results.
Article
Physics, Fluids & Plasmas
Benedikt Remlein, Udo Seifert
Summary: The study shows that for a system with discrete states, achieving an optimal driving process involves nonconservative driving, unlike in systems with continuous states. In a multicyclic network, the optimal driving affinity is limited by the number of states within each cycle.